On the Prospects of BaF₂ as a Fast Scintillator for Time-of-Flight Positron Emission Tomography Systems

Future time-of-flight positron emission tomography (TOF-PET) will be in need of ultrafast scintillation materials, with potential seen cross-luminescence (CL). BaF2, for example, shows a sub-100-ps decay time 300 photons produced per MeV. However, it poses challenges, such as medium radiation length, low photofraction, moderate light yield, and vacuum ultraviolet (VUV) around 200nm. Recent developments UV-sensitive solid-state photodetectors (SiPMs) have the to establish CL TOF PET. In this work, we aim study read out by these new VUV SiPMs, viable alternative cerium-doped lutetium–yttrium oxyorthosilicate (LYSO:Ce). order investigate prospects BaF2 TOF-PET, compare CTR $2\times 2\times $ 20 mm 3 undoped yttrium-doped crystals, readout Hamamatsu S13370–3050CN SiPMs maximum photon detection efficiency (PDE) 14% at 200nm air coupling, LYSO:Ce:Ca crystals same size. With high-frequency electronics, reached 233ps 213ps BaF2:Y, while performance was 125ps (measured HPK S14160–3050HS, PDE notation="LaTeX">$\sim 60$ % glue coupling). Conducting measurements different depth interaction positions pronounced impact on CTR. Furthermore, investigated systems TOFPET2c ASIC Geant4 simulations effective sensitivity comparisons LYSO:Ce:Ca.